When I load my home page, then click on Language, then Resume, then press the browser back button, Safari crashes (hits assert in debug).
It seems to be an issue with subframe navigation. Notice the subframe has to be replaced atleast twice for the assert to be hit.
It seems to work fine in release build.
When filing a bug about an assertion failure, please include the failing assertion in the bug summary or description :-)
*** This bug has been marked as a duplicate of 6454 ***